Site-selective red-edge spectroscopy of disordered materials and microheterogeneous systems: polymers, phospholipid membranes and proteins

For aromatic fluorophores embedded into different rigid and highly viscous media with low structural order the spectroscopic properties do not conform to classical rules. The fluorescence spectra can depend on excitation wavelength, and the excited-state energy transfer, if present, fails at the 'red' excitation edge. These Red-Edge effects are observed due to the existence of excited-state distribution of fluorophores on their interaction energy with the environment and the slow rate of dielectric relaxations. In these conditions the site-selection can be provided by variation of energy of illuminating light quanta, and the behavior of selected species can be followed as a function of time and other variables. These observations foudn extensive application in different areas of research: colloid and polymer science, photophysics and molecular biophysics. Site-selection effects were discovered for electron-transfer and proton-transfer reactions if they depend on the dynamics of the environment. In this report we concentrate on fluroescence of 3-hydroxyflavone derivatives as the probes that exhibit the excited-state proton transfer reaction. The studies in polymer films, phospholipid membranes and in complexes with proteins allow characterizing the static and dynamic disorder in these systems.

[1]  B. Bagchi,et al.  ANOMALOUS DIELECTRIC RELAXATION OF AQUEOUS PROTEIN SOLUTIONS , 1998 .

[2]  H. Frauenfelder,et al.  The energy landscape in non-biological and biological molecules , 1998, Nature Structural Biology.

[3]  S. Kinoshita.  Theory of transient hole‐burning spectrum for molecules in solution , 1989 .

[4]  M. Maroncelli,et al.  Polar Solvent Dynamics and Electron-Transfer Reactions , 1989, Science.

[5]  J. Simon.  Time-resolved studies of solvation in polar media , 1988 .

[6]  G. Weber,et al.  Failure of Energy Transfer between Identical Aromatic Molecules on Excitation at the Long Wave Edge of the Absorption Spectrum. , 1970, Proceedings of the National Academy of Sciences of the United States of America.

[7]  W. Rettig,et al.  Switching between charge- and proton-transfer emission in the excited state of a substituted 3-hydroxyflavone , 1994 .

[8]  D. F. Kelley,et al.  Proton transfer dynamics in substituted 3‐hydroxyflavones: Solvent polarization effects , 1993 .

[9]  A. Demchenko,et al.  Synthesis and spectroscopic properties of benzo- and naphthofuryl-3-hydroxychromones , 2001 .

[10]  V. Pivovarenko,et al.  Flavonols--new fluorescent membrane probes for studying the interdigitation of lipid bilayers. , 1998, Biochimica et biophysica acta.

[11]  M. Maroncelli,et al.  Dipole Solvation in Nondipolar Solvents: Experimental Studies of Reorganization Energies and Solvation Dynamics† , 1996 .

[12]  H. Tashiro,et al.  Fast structural relaxation of polyvinyl alcohol below the glass-transition temperature , 1998 .

[13]  C. Blomberg,et al.  Stretched exponentials and barrier distributions , 2000 .

[14]  R. Rigler,et al.  Memory landscapes of single-enzyme molecules. , 2000, Proceedings of the National Academy of Sciences of the United States of America.

[15]  A. Elschner,et al.  Experimental Study of Non-Exponential Relaxation Processes in Random Organic Solids , 1986 .

[16]  Aleksandr Petrovich Demchenko,et al.  Ultraviolet Spectroscopy of Proteins , 1986, 1987.

[17]  A. Demchenko.  Does biocatalysis involve inhomogeneous kinetics? , 1992, FEBS letters.

[18]  J. Vanderkooi,et al.  Fluorescence line narrowing applied to the study of proteins. , 1998, Biochimica et biophysica acta.

[19]  W. Galley,et al.  Role of heterogeneity of the solvation site in electronic spectra in solution. , 1970, Proceedings of the National Academy of Sciences of the United States of America.

[20]  A. Demchenko,et al.  Site selectivity in excited-state reactions in solutions , 1991 .

[21]  P. Chou,et al.  Reversal of excitation behavior of proton-transfer vs. Charge-transfer by dielectric perturbation of electronic manifolds , 1993 .